2.8 KiB
2.8 KiB
Capella Light Client -- Full Node
Notice: This document is a work-in-progress for researchers and implementers.
Table of contents
Introduction
This upgrade adds information about the execution payload to light client data as part of the Capella upgrade.
Helper functions
Modified block_to_light_client_header
def block_to_light_client_header(block: SignedBeaconBlock) -> LightClientHeader:
epoch = compute_epoch_at_slot(block.message.slot)
if epoch >= CAPELLA_FORK_EPOCH:
payload = block.message.body.execution_payload
execution_header = ExecutionPayloadHeader(
parent_hash=payload.parent_hash,
fee_recipient=payload.fee_recipient,
state_root=payload.state_root,
receipts_root=payload.receipts_root,
logs_bloom=payload.logs_bloom,
prev_randao=payload.prev_randao,
block_number=payload.block_number,
gas_limit=payload.gas_limit,
gas_used=payload.gas_used,
timestamp=payload.timestamp,
extra_data=payload.extra_data,
base_fee_per_gas=payload.base_fee_per_gas,
block_hash=payload.block_hash,
transactions_root=hash_tree_root(payload.transactions),
withdrawals_root=hash_tree_root(payload.withdrawals),
)
execution_branch = compute_merkle_proof(block.message.body, EXECUTION_PAYLOAD_INDEX)
else:
# Note that during fork transitions, `finalized_header` may still point to earlier forks.
# While Bellatrix blocks also contain an `ExecutionPayload` (minus `withdrawals_root`),
# it was not included in the corresponding light client data. To ensure compatibility
# with legacy data going through `upgrade_lc_header_to_capella`, leave out execution data.
execution_header = ExecutionPayloadHeader()
execution_branch = [Bytes32() for _ in range(floorlog2(EXECUTION_PAYLOAD_INDEX))]
return LightClientHeader(
beacon=BeaconBlockHeader(
slot=block.message.slot,
proposer_index=block.message.proposer_index,
parent_root=block.message.parent_root,
state_root=block.message.state_root,
body_root=hash_tree_root(block.message.body),
),
execution=execution_header,
execution_branch=execution_branch,
)